<template>
  <div class="upload-file">
    <el-upload
      multiple
      :action="uploadFileUrl"
      :before-upload="handleBeforeUpload"
      :file-list="fileList"
      :limit="limit"
      :on-error="handleUploadError"
      :on-exceed="handleExceed"
      :on-success="handleUploadSuccess"
      :show-file-list="false"
      :headers="headers"
      class="upload-file-uploader"
      ref="upload"
    >
      <!-- 上传按钮 -->
      <el-button size="mini" type="primary">选取文件</el-button>
      <!-- 上传提示 -->
      <div class="el-upload__tip" slot="tip" v-if="showTip">
        <div v-if="flag">
          <template v-if="fileSizeM"
            >请上传 单个大小不超过
            <b style="color: #f56c6c">{{ fileSizeM }}MB</b>
          </template>
          <template v-if="fileTypeM">
            格式为
            <b style="color: #f56c6c">{{ fileTypeM.join("/") }}</b>
            的文件</template
          >
        </div>
        请上传
        <template v-if="fileSize">
          单个大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b>
        </template>
        <template v-if="fileType">
          格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b>
        </template>
        的文件
      </div>
    </el-upload>

    <!-- 文件列表 -->
    <transition-group
      class="upload-file-list el-upload-list el-upload-list--text"
      name="el-fade-in-linear"
      tag="ul"
    >
      <li
        :key="file.url"
        class="el-upload-list__item ele-upload-list__item-content"
        v-for="(file, index) in fileList"
      >
        <el-link
          :href="getFileUrl(file.url)"
          :underline="false"
          target="_self"
        >
          <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
        </el-link>
        <div class="ele-upload-list__item-content-action">
          <el-link :underline="false" @click="handleDelete(index)" type="danger"
            >删除</el-link
          >
        </div>
      </li>
    </transition-group>
  </div>
</template>

<script>
import { getToken } from "@/utils/auth";

export default {
  name: "FileUpload",
  props: {
    // 是否显示格式
    flag: {
      type: Boolean,
    },
    // 值
    value: [String, Object, Array],
    // 数量限制
    limit: {
      type: Number,
      default: 5,
    },
    // 大小限制(MB)
    fileSize: {
      type: Number,
      default: 5,
    },
    fileSizeM: {
      type: Number,
      default: 10,
    },
    // 文件类型, 例如['png', 'jpg', 'jpeg']
    fileType: {
      type: Array,
      default: () => ["doc", "pdf"],
    },
    fileTypeM: {
      type: Array,
      default: () => [],
    },
    // 是否显示提示
    isShowTip: {
      type: Boolean,
      default: true,
    },
  },
  data() {
    return {
      number: 0,
      uploadList: [],
      download: process.env.VUE_APP_BASE_API + "/file/download/", //下载地址
      uploadFileUrl: process.env.VUE_APP_BASE_API + "/file/upload", // 上传的图片服务器地址
      headers: {
        Authorization: "Bearer " + getToken(),
      },
      fileList: [],
    };
  },
  watch: {
    value: {
      handler(val) {
        if (val) {
          let temp = 1;
          // 首先将值转为数组
          const list = Array.isArray(val) ? val : this.value.split(",");
          // 然后将数组转为对象数组
          this.fileList = list.map((item) => {
            if (typeof item === "string") {
              item = { name: item, url: item };
            }
            item.uid = item.uid || new Date().getTime() + temp++;
            return item;
          });
        } else {
          this.fileList = [];
          return [];
        }
      },
      deep: true,
      immediate: true,
    },
  },
  computed: {
    // 是否显示提示
    showTip() {
      return this.isShowTip && (this.fileType || this.fileSize);
    },
  },
  methods: {
    // 上传前校检格式和大小
    handleBeforeUpload(file) {
      const toType = file.name.slice(file.name.lastIndexOf(".") + 1).toLowerCase()
      // 校检文件类型
      if (this.fileType || this.fileTypeM) {
        let fileExtension = "";
        if (file.name.lastIndexOf(".") > -1) {
          fileExtension = toType
          if (fileExtension == "xlsx") {
            this.$modal.msgError(
              `文件格式不正确, 请上传${[
                ...this.fileType,
                ...this.fileTypeM,
              ].join("/")}格式文件!`
            );
            return false;
          }
          // 判断上传文件的类型大小
          if (
            fileExtension == "doc" ||
            fileExtension == "docx" ||
            fileExtension == "pdf"
          ) {
            const isLt = file.size / 1024 / 1024 < this.fileSize;
            if (!isLt) {
              this.$modal.msgError(
                `上传${this.fileType}文件大小不能超过 ${this.fileSize} MB!`
              );
              return false;
            }
          } else {
            // 判断是否需要传入MP3.MP4格式的文件，不需要就不判断
            if (this.flag) {
              if (fileExtension == "mp3" || fileExtension == "mp4") {
                const isLtM = file.size / 1024 / 1024 < this.fileSizeM;
                if (!isLtM) {
                  this.$modal.msgError(
                    `上传${this.fileTypeM}文件大小不能超过 ${this.fileSizeM} MB!`
                  );
                  return false;
                }
              }
            }
          }
        }
        const isTypeOk = [...this.fileType, ...this.fileTypeM].some((type) => {
          if (file.type.indexOf(type) > -1) return true;
          if (fileExtension && fileExtension.indexOf(type) > -1) return true;
          return false;
        });
        if (!isTypeOk) {
          this.$modal.msgError(
            `文件格式不正确, 请上传${[...this.fileType, ...this.fileTypeM].join(
              "/"
            )}格式文件!`
          );
          return false;
        }
      }
      // 校检文件大小
      // if (this.fileSize) {
      //   const isLt = file.size / 1024 / 1024 < this.fileSize;
      //   if (!isLt) {
      //     this.$modal.msgError(`上传文件大小不能超过 ${this.fileSize} MB!`);
      //     return false;
      //   }
      // }
      this.$modal.loading("正在上传文件，请稍候...");
      this.number++;
      return true;
    },
    // 文件个数超出
    handleExceed() {
      this.$modal.msgError(`上传文件数量不能超过 ${this.limit} 个!`);
    },
    // 上传失败
    handleUploadError(err) {
      this.$modal.msgError("上传图片失败，请重试");
      this.$modal.closeLoading();
    },
    // 上传成功回调
    handleUploadSuccess(res) {
      if (res.code == 200) {
        this.uploadList.push({
          name: res.data.url,
          url: this.download + res.data.id + "_" + res.data.name,
        });
        if (this.uploadList.length === this.number) {
          this.fileList = this.fileList.concat(this.uploadList);
          this.uploadList = [];
          this.number = 0;
          this.$emit("input", this.listToString(this.fileList));
          this.$modal.closeLoading();
        }
      }
    },
    // 删除文件
    handleDelete(index) {
      this.fileList.splice(index, 1);
      this.$emit("input", this.listToString(this.fileList));
    },
    // 获取文件名称
    getFileName(name) {
      if (name.lastIndexOf("_") > -1) {
        return name.substring(name.indexOf("_") + 1, name.length);
      } else {
        return "";
      }
    },
    // 获取文件地址
    getFileUrl(url) {
      if (url.lastIndexOf("_") > -1) {
        return url.substring(0, url.indexOf("_"));
      } else {
        return "";
      }
    },
    // 对象转成指定字符串分隔
    listToString(list, separator) {
      let strs = "";
      separator = separator || ",";
      for (let i in list) {
        strs += list[i].url + separator;
      }
      return strs != "" ? strs.substr(0, strs.length - 1) : "";
    },
  },
};
</script>

<style scoped lang="scss">
.upload-file-uploader {
  margin-bottom: 5px;
}
.upload-file-list .el-upload-list__item {
  border: 1px solid #e4e7ed;
  line-height: 2;
  margin-bottom: 10px;
  position: relative;
}
.upload-file-list .ele-upload-list__item-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: inherit;
}
.ele-upload-list__item-content-action .el-link {
  margin-right: 10px;
}
</style>
